1. Field of the Invention
The present invention relates generally to input of a password used for personal identification (authentication), and, more particularly, to an electronic apparatus able to perform password input with a simple input operation and a recording medium storing a password input program.
2. Description of the Related Art
When using various electronic apparatuses such as a personal computer, databases, information services, etc., a password such as an identical number is frequently used to authenticate a particular user, etc. This password is input by operating keys assigned with characters and symbols representing the password.
With regard to such password input and authentication thereof, Japanese Patent Application Laid-Open Publication No. H07 (1995)-210286 discloses that: in order to prevent that some keys not used on a keyboard are operated carelessly, a table directing key function to be invalid is provided for function of keyboard; it is checked whether or not invalidation is directed to key information generated by key operation of the keyboard by the table; if the key information is directed to be invalid, mask processing is carried out for the key information (abstract, paragraph No. 0002, FIG. 1, etc.).
Japanese Patent Application Laid-Open Publication No. 2000-29609 discloses generating password input display and a dummy symbols with use of random numbers, and arranging the password input display and the dummy symbols randomly (abstract, FIG. 2, etc.).
Japanese Patent Application Laid-Open Publication No. H05(1993)-224802 discloses that private codes and dummy codes are displayed on keytops randomly to compare codes inputted in series from the keytops with private codes stored in a private code storing circuit (abstract, FIG. 1, etc.).
By the way, in the invalidation of the key function of the keyboard (Japanese Patent Application Laid-Open Publication No. H07(1995)-210286), and the random arranging display of the password, private codes and dummy symbols, dummy codes (Japanese Patent Application Laid-Open Publication Nos. 2000-29609 and H05 (1993)-224802), since a user must respond to the invalidated key and the display thereof and it takes time to input a password, the password may be recognized by other persons from the operation. As the number of characters of a password is increased, it may take more time to input the password.
If keys corresponding to candidate characters of a password are required for inputting the password, the number of the keys must correspond to the number of the characters constituting the password and the password may be stolen by other persons.
Japanese Patent Application Laid-Open Publication Nos. H07 (1995)-210286, 2000-29609 and H05 (1993)-224802 do not disclose or indicate such problems and do not disclose means for solving the problems or do not include a concept thereof.